package com.cwg.dict.service;

import java.util.List;
import java.util.Map;

import com.cwg.dict.model.History;

public interface Historical {

	List<History> listBefore(int dayAgo);

	/**
	 * list top history which sorted by date.
	 * @param  amount 0 for all history.
	 * @return latest N history
	 */
	List<History> listLatest(int amount);

	Map<String, Integer> statistic();

}
